CONCERNING PROTOPLASM. 65 



ceivable form, or as possessing no definite shape at all, we see the 

 animalcule known as the Amoeba (Fig. 20) a form which has had 

 the honourable distinction of providing a most typical illustration 

 of lower life for all stages of biological teaching and instruction. The 

 name Amoeba signifies change. Of old, the being in question, drawn 

 from the stagnant drop, and placed under the object-glass of our micro- 

 scope, was named the " Proteus animalcule j " and its more modern 

 cognomen testifies to the same characteristics of alteration and change 

 described by the Protean simile of former days. A mere microscopic 

 speck is the being before us, its size being measurable only in the hun- 

 dredths of an inch. It will require some diligent looking ere its trans- 

 parent body be clearly discerned. For it seems now and then to merge 

 into the water amid which it lives and moves, and appears frequently 

 to fade away into physical nothingness, just as in the sense of its 

 vitality it may be said to hover on the verge of existence itself. 

 When the eye lights upon the Amoeba, and becomes accustomed to 

 the dim outlines it exhibits, we are enabled likewise to note the 

 prevailing characteristic of the animalcule in the continual tendency 

 to well-marked physical change and contraction which its body 

 exhibits. At no one period can it be described as exactly resem- 

 bling its look or appearance at any previous stage of existence. 

 Each moment brings new changes of shape (Fig. 20, b) and transmuta- 

 tions of outline. Now it has launched forth its soft body in one 

 direction until it appears in a long-drawn-out line ; now it has drawn 

 this same body forwards, and has protruded its soft substance on each 

 side into so many processes, that it resembles some solitary island with 

 capes, headlands, and promontories jutting out in a sea of its own. 



We note an animalcule, of, it may be, higher organisation than 

 itself, to approach the Amoeba. There is a momentary contact of the 

 foreign body with the soft protoplasm of the Amoeba, and instantly 

 the latter extends its frame outwards so as to encompass the living 

 particle, which is shortly engulfed within the contractile mass. 

 Protoplasm is thus seen to live on protoplasm a procedure which, by 

 the way, in higher animal life is exactly repeated and imitated in its 

 essential details. By this process of surrounding and enclosing its 

 food-particles within its body, our Amoeba obtains its nutriment; and 

 one may well imagine the horror which the appearance of this gelati- 

 nous monster, engulfing, like some formless octopus, all that came in 

 its way, would excite in lower life, were the processes of thought and 

 thinking extant among the animalcular worlds. Thus, also, we see 

 how the Amoeba, like so many of its near neighbours, nourishes itself in 

 the absence of a mouth and digestive system j feels, whilst it wants 

 even the first beginnings of nerves ; and moves, despite the fact that 

 no organs of motion are developed. Watch the food-particle that 

 has just been enclosed within the soft frame, and in due time you 



